The invention relates to a trench sheeting device consisting of trench sheeting boxes that are each made up of two standard trench plates that are supported against each other, the width of the trench apart, with the help of spindle spreaders, said device having at least one shaft sheeting box whose width exceeds the width of the trench, measured crosswise in relation to the longitudinal direction of the trench and comprises a standard trench plate on each wall of the shaft, as well as shaft plates detachably attached upright to the longitudinal ends of each of the trench plates transversely in relation to the longitudinal direction of the trench, said detachable shaft plates being coupled with the trench plates of an adjoining trench sheeting box after they have been driven into the ground.
In trench sheeting, for example for laying pipeline ducts, trench plates are supported against each other in pairs with the help of spindle spreaders. The individual trench plate generally has a rectangular shape. At its bottom, which has to be driven into the ground, it has a blade, and at the top edge opposing the blade, thus on the so-called anvil edge, it is provided with a stability such that it can be driven into the ground with the shovel of the excavator. On the side edges, which extend about vertically after it has been installed, such a trench plate may have tabs for connecting it with trench plates disposed adjacent to it in the longitudinal direction of the trench, such tabs generally being located on the inside surface facing the trench and being solidly molded onto, in particular welded to the side edges. In addition, provision is made on the inside surfaces of each trench plate for bearing positions for receiving the spindle spreaders. A spindle spreader is a punch that has a screw spindle, for example in the center. The punch can be made longer or shorter with the help of such a screw spindle. For forming a trench sheeting box, a pair of trench plates is generally stabilized by four spindle spreaders.
Trenches, often several meters deep, on whose bottom tube ducts, for example for waste water canals have to be installed, are produced with the help of a trench sheeting device that weighs tons. Inspection shafts are required along the course of a canal at defined intervals. Such shafts are often constructed of brickwork and their diameter is in general substantially larger than the diameter of the respective pipeline. Over the major part of its length, i.e. where only the canal tubes have to be laid, the trench, for reasons of savings, is made just wide enough as required for laying the canal tubes. Such a trench width is in most case not sufficient to allow the construction of an inspection shaft, in whose location the spacing measured crosswise in relation to the, longitudinal direction of the trench plates that are supported against each other, needs to be substantially larger than in the remaining part of the trench. In practical life, the transition from the normal width of the trench to the greater width required for the shaft poses problems. Since investments for special parts for producing a shaft box enclosing the location of an inspection shaft to be built are preferably avoided, all sorts of risky auxiliary means are often employed for supporting the site of the shaft. As an alternative, the trench is often constructed already with a spacing provided from the location intended for the inspection shaft by expanding it to the width of the shaft, to begin with. This means that either the risk of collapse is posed, or that considerably more soil has to be carted off than would be actually required for constructing the canal and the shaft.
A trench sheeting device which possibly may comprise an integrated shaft sheeting box is disclosed in EP-A-0 027 576. According to said published document, an expansion can be installed in a number of trench sheeting boxes having a normal width. Trench plates (sheeting plates) can be used on the sides of said expansion like in a trench having a normal width. For compensating the changing width of the trench, connecting pieces that can be lengthened like a telescope are used at the ends of the trench plates via vertically adjustable clamping shoes. The connecting pieces have bores at their longitudinal ends. Bolts are associated with the bores at the substantially vertical longitudinal ends of the (installed) trench plates. After the trench plates have been installed, each two adjacent longitudinal edges are coupled with each other by connecting two bolts that oppose each other on adjacent walls with one of the connecting pieces, whereby the two bores of the connecting piece are hooked up via the bolts. The horizontal spacing of the two bores can be adapted to the actual spacing of the bolts by changing a telescope that is integrated in the connecting piece. It is stated in the prior art that any vertical offset between adjacent installation plates can be compensated with the help of a vertically adjustable clamping connection consisting of a clamping shoe (on the one plate) and an associated clamping rail (on the other plate).
According to the aforementioned EP-A-0 027 576, it is possible in the manner described to compensate part of the inaccuracies that always occur when the trench plates are driven into the ground. However, for compensating driving-in inaccuracies in the direction of the depth, width and length of the trench, three different auxiliary means with screw and clamp connections that have to be mounted in the trench are required in the prior art. Such adapting means are unsuitable for the rough underground construction operations involving protection, rust and frequent bending stresses.
In addition to the connecting components which are difficult to assemble, it is necessary in the prior art according to the above-cited published document to drive a canal piling into the ground; however, gaps remain nonetheless open along the borderlines between the standard trench plates and the canal piling, through which sandy subsoil may trickle into the shaft. The known device, however, is not only difficult to assemble after it has been driven into ground: such assembly is often not possible at all, and, furthermore, it also requires much expenditure on account of the complicated telescopic component, and comprehensive stockkeeping of special parts is required because of the variety of individual parts.
The invention is based on the problem of providing a shaft sheeting box that has to be integrated in a normal trench sheeting construction, thus a sheeting construction consisting of standard trench plates. Such a shaft sheeting box can substantially make do with standard trench plates, so that the amount of soil to be excavated and the risk of collapse are minimized.
Furthermore, precautionary measures are to be implemented that permit compensating inaccuracies occurring when the shaft sheeting box or the preceding trench sheeting box are driven into the ground, using means suited to underground civil engineering.
The solution according to the invention for the trench sheeting device specified above, with trench sheeting boxes successively arranged along the trench, and with at least one shaft sheeting box, consists in that the shaft sheeting box, before it is driven into the ground, is set up upright with attached shaft plates as a structure with a U-shaped horizontal cross section appearing like one single part, and in that the coupling of each shaft plate with the adjoining trench plate consists of a vertically disposed first bolt as well as a second bolt, the latter being in each case horizontally movable versus the trench plate or the shaft plate and supported on the latter, and vertically movably connected with the first bolt. Some improvements and further developments of the invention are described in the dependent claims.
Therefore, a trench sheeting box as defined by the invention consists of two structures which, upon their installation, have an approximately U-shaped cross section, whereby the base lines of the U-shape formed by standard trench plates are maintained by conventional spindle spreaders at such a mutual spacing that the mutual spacing of the free ends of the U-legs opposing each other, which are the free vertical edges of the shaft plates, has approximately the same size as the normal width of the trench, such mutual spacing being the one of the trench plates in the normal part of the trench where only a tube has to be laid.
The shaft plates as defined by the invention are basically structured similar to standard trench plates; however, they are much narrower than the normal trench plates in the horizontal direction, measured on the plate in its set-up position. Also, in practical life, the utilization of such plates is not limited to their application in connection with shaft boxes; they are rather employed whereever trench plates with less than the normal length are needed. Therefore, a shaft sheeting box as defined by the invention can be assembled with the help of components available at the construction site.
According to the invention, the shaft plate is joined with the trench plate via a form-locked bolt-and-eye coupling in such a way that the structure comprising two shaft plates and one trench plate set up upright to form a xe2x80x9cUxe2x80x9d can be driven into the ground without being capable of moving within itself, acting rather like one single part. For said purpose, the shaft plate, like the trench plate, has a blade on the bottom edge. The coupling belonging to the shaft sheeting box, with the shaft plates to be attached to its two longitudinal ends, preferably consists of a bolt-plug connection, which is geometrically designed and adapted to the shape of the plate edges bordering on each other, in such a way that after the bolt has been plugged in, any mutual movement between the trench plate and the shaft plate is excluded.
An shaft sheeting box with two standard trench plates opposing one another, and with a total of four shaft plates immovably attached to the longitudinal ends of the trench plates, is set up in the upright position with the help of the spindle spreader for producing a shaft, and driven into the ground into the intended position adjoining the last preceding trench box, whereby the soil is excavated with an excavator to the required extent, or removed in some other way. For implanting the shaft sheeting box, it is made sure that the free ends of the U-legs (shaft plates) of the shaft sheeting box, said free ends facing each other, are positioned with as much accuracy as possible, adjoining the free longitudinal ends of the trench sheeting box, the latter having been implanted first. After this work operation has been completed, the free ends of the U-legs are coupled with the free ends of the trench plate of the neighboring trench sheeting box.
According to the invention, measures are implemented in the coupling site where the shaft box is coupled with the trench box, such measures permitting inaccuracies to be compensated that were caused when the shaft sheeting box was driven into the soil, or when the trench sheeting box was driven in first. Preferably, provision is made between the shaft plate and the adjacent trench plate for a coupling with a vertically disposed rail of the trench plate as well as a carriage, the latter being horizontally movable versus the shaft plate and supported on the latter, whereby the carriage has to be vertically movably connected with the rail (alternatively, the rail can be secured on the shaft plate and the carriage can be supported on the trench plate). Such a connection permits to compensate inaccuracies that are often in the order of magnitude of a few centimeters, both in the horizontal and vertical directions.
Said embodiment of the invention is made particularly simple if both the rail and the carriage are realized in the form of bolts, and if the bolt forming the carriage grips with an eye over the bolt forming the rail. If the eye encloses the rail with play, the coupling as defined by the invention is capable of producing the joint in said site in a stable way even if the plate planes are positioned in the ground turned angularly against each other. For compensating horizontal displacements of the shaft box versus the adjacent trench box, it may be favorable, furthermore, if the bolt forming the carriage grips through a horizontal slot of the shaft plate and is secured on the shaft side against the forces originating from the trench plate by an abutment (the aforementioned alternative is applicable also with respect to the slot, i.e. with an exchange between the trench and shaft plates).